compositor: Drop legacy backends in favor of libinput

Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/Makefile.am b/Makefile.am
index 2fc171e..e942850 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -184,25 +184,12 @@
 x11_backend_la_SOURCES = src/compositor-x11.c
 endif
 
-INPUT_BACKEND_SOURCES = src/udev-input.h
-
-if ENABLE_LIBINPUT_BACKEND
 INPUT_BACKEND_LIBS = $(LIBINPUT_BACKEND_LIBS)
-INPUT_BACKEND_SOURCES +=			\
+INPUT_BACKEND_SOURCES =				\
 	src/libinput-seat.c			\
 	src/libinput-seat.h			\
 	src/libinput-device.c			\
 	src/libinput-device.h
-else
-INPUT_BACKEND_SOURCES +=			\
-	src/filter.c				\
-	src/filter.h				\
-	src/udev-seat.c				\
-	src/udev-seat.h				\
-	src/evdev.c				\
-	src/evdev.h				\
-	src/evdev-touchpad.c
-endif
 
 if ENABLE_DRM_COMPOSITOR
 module_LTLIBRARIES += drm-backend.la